Air conditioning apparatus



Jan. 16, 1940. p, GQGGINS 2,187,397

AIR CONDITIONING APPARATUS Filed Sept. 7, 1937 3 SheetsSheet 1 INVENTOR James oy/ Jan. 16, 1940. p. GOGGINS 2,187,397

AIR CONDITIONING APPARATUS Filed Sept. '7, 1937 3 Sheets-Sheet 2 INV EN TOR DIHWW ATTRNEY mes R Gayy/ns I Patented Jan. 16, 1940 PATENT OFFICE AIR CONDITIONING APPARATUS James P. Goggins, Omaha, Nelm, minor to Interstate Transit Linea-Omaha, Nebr., a corporation of Nebraska Application September 7, 1937, Serial No. 162,601

7 Claims.

My invention relates to air conditioning apparatus and more particularly to an air condition: ing assembly actuated automatically by an internal combustion engine, the arrangement being of 5 such flexibility and compactness that it is espe: cially adapted for use in the air conditioning of passenger vehicles such as automobile GL1?- other automobile vehicles, ships, airpl "if: like, as well as private dwellings, hot W and office buildings. I I tlurrently, air conditioning is being wi remains costly to oper t of experts vehicles, electric power is n natural and convenient sour or" power .l

ternai combustion engine r rich highly veloped. Une of the major requirements an air conditioning system is that it maintains a constant temperature automatically response to a thermostat. The difficulty or starting stopping an internal combustion engi to operate the compressor of a refrigerating system of the air conditioning assembly has been such that those systems which employed an in ternal combustion system as power resorted to constantly running engine adapted to be clutched and unclutched from the load. The use or": a clutch has been found very unsatisfactory. The clutch rapidly wears and the necessity of constantly running the internal combustion engine made the operation inefilcient.

in modern motor transport, such as an automobile omnibus, the problem is extremely dimcult. Various state laws exist, limiting the high- 35' way axle weights.

which can be used upon a motor bus must therefore be light in weight. The space on a motor bus is limited, there being about 1200 cubic feet available in all, to take an illustrative example. Of this space, 700 cubic feet are occupiedby the passengers. Inasmuch as the passenger space is usually fairly well filled with human beings, it is necessary, to insure that a comfortable temperature be maintained, to circulate about 600 cubic feet of air per minute. This air cannot be constantly recirculated as it will soon become foul. It has been found that about 200 cubic feet of fresh air per minute must be taken in and the same amount discharged from the body of circulating air in order to maintain the health and comfort of the passengers. It has been found that the air conditioning assembly, in addition to being light and compact, must be capable of producing the equivalent of between four and 5 five tons of refrigeration,

Any air conditioning system One object of my invention is to provide an air conditioning assembly which is powered by an internal combustion engine in which the engine operates only when required.

Another object of my invention is to provide 5 7 air conditioning assembly powered by an internal combustion ngine w nch is entirely auto-- 1 such that the en di on an .0. le omnibus. Another object of my invention is to provide an air conditioning assembly powered by an in ternal combustion engine in which a clutch with its attendant disadvantages is eliminated.

@ther and further objects or" my invention the following description.

the accompanying drawings which form part of the instant specification and are to read in conunction therewith and in which like reference numerals are used to indicate like parts in the various views;

Figure l is a diagrammatic View of an air con ditioning assembly showing one embodiment my invention, with the parts in the starting position, the electric conducto's carrying current being shown in heavy lines.

Figure 2 is a diagrammatic view similar to Figure l, with the parts in running position.

Figure 3 is a sectional elevation of a control element forming part of my assembly.

Figure 4 is a sectional view taken along the line i--4 of Figure 3.,

Figure 5 is a sectional view taken along the line 5-5 of Figure 4.

Figure 6 is a sectional view of the high-low control forming a part of my assembly.

Figure 7 is a fragmentary view on an enlarged scale, with parts in section, of another control element forming part of my air conditioning assembly.

Figure 8 is a fragmentary view of a detail of my assembly.

In general, my invention contemplates the provision of a commutator or control switch, actuated in response to the operation of an internal combustion engine whereby a thermostat will close proper circuits through the commutator to start the internal combustion engine, and when the engine has been started, will permit it to run until the air conditioning requirements of the space being conditioned have been satisfied, at

which time the internal combustion engine will be caused to stop. Provision is made to unload the compressor as soon as it stops so that the engine may start under substantially no load, the arrangement being such that when the engine is running, the unloading device is automatically operated to permit the compressor to function.

More particularly, referring now to the drawings, an internal combustion engine I is provided with the usual carburetor 2, to which fuel is fed through a fuel line 3. The internal combustion engine has spark plugs 4, furnished voltage through the usual distributor arm 5, moving in timed relation with contact points 6. Potential is supplied to the primary 1 of an induction coil from a battery 8, which in the case of an automotive vehicle, may be the vehicle battery. A customary interrupter 9 is provided to make and break circuit through the primary 1, whereby an electromotive force will be induced in the secondary l8 of the induction coil for distribution to the spark plugs 4 of the engine I. The air intake to the carburetor is shown at H and is provided, with a choke |2. The engine drives a governor shaft l3 through any suitable connection such as belt H. The governor |5 tends to close the throttle l6 against the action of spring IT. The engine is adapted to be started by an electric starting motor l8, as is well known to the art. The engine I actuates the compressor l9 of the refrigeration system of the assembly. The compressed refrigerant, when the system is in operation, leaves the compressor through line 20, passes through check valve 2|, line 22, through condenser coil 23, which is positioned in a casing 24, through which air is adapted to be blown by blower 25. Water is sprayed over the condenser 23 from any suitable means such as a spray head 26. The condensed refrigerant fluid leaves the condenser through line 21 and passes into a liquid reservoir 28, whence it leaves through line 29, passing through a strainer 38, and thence through a dryer 3|, it being understood dryer by-pass valve 32 is normally closed. The refrigerant fluid leaves the dryer through line 33 and passes through line 34, through a sight feed glass 35, through a magnetically controlled valve 36 into the manifold 31. The compressed, condensed refrigerant fluid passes through thermostatic expansion valves 38, through lines 39, through refrigerating coils 40, over which the air to be conditioned is passed by fans 4|. The refrigerant fluid leaves the refrigerating coils 40 and passes into the manifold 42, whence it leaves through line 43 and passes to the compressor suction pipe line 44. It will be noted that the compressor discharge line 20: and the compressor suction line 44 are provided with an intercommunicating line 45. controlled by a solenoid operated valve 46. The valve 48 is an unloader valve, permitting the suction side of the com-- pressor and the discharge side of the compressor to communicate and thus relieve any load upon the compressor. The valve 46, during operation, is normally closed. The engine drives a generator 41 through any suitable means such as a belt 48, .the output of the generator being used to actuate motor 49, which drives the blower 25 through a belt 50.

Water for passage over the condenser 23 is supplied from a water supply tank 5| by pump water in the casing 24 is pumped through line 55 by pump 58 for return to the water supply tank 5|, the pump 58 being driven by a motor 51, through any suitable means such as a belt 58.

Moisture precipitated from the air being conditioned is collected in pans 59 and collected in a manifold 60 for passage through pipe 6| to the water supply tank 5|. A pipe 82 communicates with the discharge pipe 20 of the compressor l9 and impresses the discharge pressure upon a high-low control 83 A pipe 84 provides communication between thesuction line 44 of the compressor l9 and the high-low control 69. A pipe 64' provides communication between the compressor suction line 44 and the Sylphon bellows of the modulated engine speed control device by which the tension of the governor spring I! is modified in accordance with load requirements as will hereinafter be more fully pointed out. The choke I2 is operated by a solenoid 66. The valve 36 is operated by a solenoid 61. The unloader valve 48 is operated by a solenoid 58.

A starting motor I8 is adapted to operate from battery 8 and is controlled by a switch 69 which is operated by a solenoid Hi. The commutator or control switch of the system is indicated generally by the reference numeral M. It is provided with commutator bars 12 adapted to make contact with contact points 13 and 14, commutator bar 15 adapted to make contact with contact points 18 and 11, commutator bar 18 adapted to complete the circuit between contact points 19 and 88, commutator bar 8| adapted to complete a circuit between contact points 82 and 83, and commutator bar 84 adapted to complete a circuit between contact points 85 and 88. The control switch is adapted to be actuated in response to the operation of the engine. As shown in Figure l, a cylinder 81 houses a piston 88.

A piston is normally urged downwardly by a through line 98 above the piston 38 will permit atmospheric pressure to lift the piston moving the commutator or switch member upwardly to the position shown in Figure 2. It is to be understood that any suitable means for operating the switch or commutator member as afunction of the operation of the engine may be employed. For example, referring now to Figure 8, the engine drives a pneumatic pump 92 through any suitable means such as a belt 93. The pipe may be placed in communication with the pump 92 through line 94 by means of a valve 95, it being understood that, in such case, the valve 96, which provides communication with the intake manifold 9| of the engine, is closed. The pump 92 of course may be a pressure pump in which case the pipe 99 will communicate below the piston 88 as will be readily understood by those skilled in the art.

Considering now the electrical circuits which.

a control panel 91, located in the air space being conditioned.v In the case of a vehicle, the panel 91 will be situated in full view of the vehicle operator. on the panel 91 is mounted a master pilot light 98, a starting pilot light 99 and a running pilot light I00. A thermostat "II is also mounted upon the control panel as is a master switch I02, a unit switch I03, and an aircirculating fan switch I04. A push button I05 is adapted to be operated manually to close the circuit through the choke solenoid 66. The engine assembly is usually located remote from the air space being conditioned. In order that the engine may be tested when desired, I provide an engine panel I06 on which I mount a choke switch I01 paralleling the push button I05, a starter testing switch I08 paralleling contact point I6, and a test operating switch I09 paralleling the thermostat IN, the master switch I02 and the unit switch I03.

One side of the battery 8 is connected by conductor IIO to conductor III and contact point I I2 of the starting switch 69 The starting switch Conductor III is connected to conductor I 20, by which conductor I2I is adapted to be connected to the battery through master switch I02, thermostat IOI, unit switch I03. The conductor I20 is connected to lead I22 to which contact points 16, I9, and 85 of the control switch are connected. Conductor I23 is connected to conductor I20 before the thermostat IM and to conductor I23 contact points I3 and 82 of the com- I mutator switch are connected.

The electrical circuits involved can be most easily understood from a description of the operation of the assembly.

Referring now to Fig. 1, it will be noted that the master switch I02 and the unit switch I33, as well as the thermostat IIiI are closed. The assembly has not been operating and the air space to be conditioned is warm. The master switch I02 has just been closed. When the device is not operating, the engine of course is not operating and the spring 89 Will move the control switch or commutator to the position shown in Figure l. The switch having been closed, current will flow from the battery 3 through conductor II 0, through conductor III, through conductor I20, through master switch I02, through conductor I23, through thermostat IOI, through conductor I25, through unit switch I03, through conductor I2I, through conductor I 22 to contact point I6, through commutator bar I5 to contact point II, through conductor I26, through thermostatic element I28, through conductor I29, through winding I0, through conductor I I4, through the starting motor I8, through conductor II5, to ground I I6, and thence to the other side of the battery. The winding I being energized, the armature I30 will lift to close switch 69. The starting motor I8 will then be placed across the battery 8 and current will flow through conductor IIO, switch 69, conductor I I4, through the motor I 8, through conductor H5, ground II 6, and thence to the other side of the battery, actuating the starting motor I8. Conductor I3I is connected to one side of the starting pilot light 99, the other side of which is connected by conductor I32 to ground I33. It will be obvious, also, that current will also flow through the starting pilot light 99. If the engine is cool and has notbeen operating, it may be desirable to choke the same. The operator may press push button switch I05, completing a circuit through conductor I I I, conductor I20, conductor I20, thermostat IOI, conductor I26, conductor I34, push button switch I 05, conductor I35, through the solenoid 66. operating the choke I2.

Current also flows from conductor I22 through contact point I9, commutator bar 18, contact point 80, conductor I36, to the primary I of the ignition induction coil, thence through interrupter 9 to ground I31, back to the other side of the battery.

It will be obvious that ignition energy is supplied to the engine I and the engine is being turned over by the starting motor I8. The operator will operate the choke I manually, as desired. Should the engine fail to start for any reason, the thermostatic element I28 will become heated and will break the circuit through the solenoid I0, interrupting the circuit through the starting motor. The interrupter I28 is merely a cranking timer to prevent running down battery 8 or burning out the windings of the starting motor I8.

It will also be noted that, independently of the thermostat, current will flow through conductor III, conductor I20, master switch I02, conductor I23, contact point I3, commutator bar 12, contact point 14, conductor I38, through the solenoid 68 of the unloader valve 46 to ground I39 and thence to theother side of the battery 8. As long as current is flowing through solenoid 68, the unloader valve 46 will be held in open position, insuring that the compressor I9 is unloaded. This enables the engine to start under no load conditions.

As soon as the engine I has started, the reduction in pressure existing in the intake manifold 9I will be communicated through pipe 90 to, the cylinder 81 of the control switch, permitting it to move to the position shown in Figure 2, to which reference will now be had. It will be noted that commutator bar I2 has moved away from contact points I3 and M, thus breaking the circuit through the solenoid 68, and permitting the unloader valve 46 to seat, thus placing the compressor in operative condition. It will also be noted that commutator bar I5 has moved upwardly and broken the circuit across contact points I6 and TI, thus deenergizing the winding II? of the starting switch 69, permitting the starting motor I 8 to stop. It will also be noted that the commutator bar I8 has moved away from contact points I9 and 80, so that potential to the ignition coil is no longer supplied through conductor I35. It will be obvious, however, that commutator bar BI has made contact between contact points 82 and 83, so that current is flowing through conductor H0, through conductor III, through conductor I20, through master switch I02, through conductor I23, through contact point 82, through commutator bar I3I, through contact point 83, through conductor I33, through high-low control 63, through conductor I40, to the primary 1 of the ignition induction coil, through the interrupter 9 to ground I31. The arrangement is such that commutator bar 8I makes contact with contact points 32 and 83 before commutator bar I8 breaks contact with contact points I9 and 80, the ignition being transferred by the upward movement of the master control switch through a circuit including the high-low control 63.

It will also be observed that commutator bar 84 has made contact with contact points 85 and 86, so that current will fiow from the battery 8 through conductor H0, conductor I I I, 'conductor I20, master switch I02, conductor I24, therniostat IOI, conductor I25, unit switch I03, conductor I2I, contact point 05, commutator bar 84, contact point 86, conductor I4I. through the winding 61 to ground I42, and thence to the other side of the battery 8 through ground IIS. Energization of the winding 61 actuates armature I43 to move valve 36 to open position, it being understood that the valve is normally urged to closed position by any suitable means. The interruption of the circuit between contact points I6 and I1 interrupts the circuit through starting pilot light 99. Winding 61 is paralleled by conductor I44 which is connected to the running pilot light I00, the circuit being completed through conductor I32 to ground I33. It will also be observed that whenever the master switch I02 is closed, the master pilot light 98 is connected to one side of the battery through conductors I24 and I46 so that pilot light 98 will be energized by the passage of current to the other side of the battery through conductor I32 and ground I33.

The engine I drives a compressor I9 which compresses the refrigerant fluid which passes through the cycle hereinabove described. v The generator 41 will furnish current for the actuation of motors 57, 49, and 54, which operate the evaporative condenser. The switch I04 is closed, permitting current to flow from the battery through conductor I41 to supply the current to the motors I48, which operate the circulatin air fans 4|. It will be observed that the motors I48 are supplied current from the battery 8 so that, if desired, air may be circulated after the engine I has stopped.

After the system has been operating and the predetermined temperature to which the thermostat IOI is set has been reached, the thermostat will open the circuit through conductors I24, I25, I2I, contact point 85, commutator bar 84. contact point 35, conductor I4I, thus deenergizing the winding 61 and permitting the valve 35 to close. This circuit is the only one broken by the thermostat after the engine is running, it being observed that the ignition is supplied independently of the thermostat. As soon as valve 36 closes, the pressure in the discharge pipe 20 leading from the compressor I9 tends to build up. At the same time, the suction pipe 44 leading to the compressor becomes exhausted. The difierential pressure existing between the suction and discharge, operates the high-low control shown in detail in Figure 6 and permits contact points I and I5I to separate, thus breaking the ignition circuit and stopping the motor. The evacuation of the suction line is an important feature. By locating check valve 2| in the discharge pipe 20 close to the compressor, only a small volume of high pressure gas need be distributed and I provide an evacuated low pressure side in which the comparatively small volume of high pressure gas may expand. This insures a substantially complete unloading of the compressor enabling ready starting of the engine when the thermo-' stat again closes. As soon as the engine stops running, the master control switch or commutator will again assume the position shown in Figure l, permitting the energization of the winding 68, moving the unloader valve to open position, permitting distribution of a comparatively small volume of high pressure gas through a well evacuated low pressure line. The starter circuit and the ignition circuit are both controlled by the thermostat so that when the engine stops in response to the opening of the thermostat l0I,

the compressor is immediately unloaded and the assembly stands ready to again operate whenever the thermostat closes. Since the engine has been warmed up by running. it will probably be unnecessary to use the choke push button.

The cranking pilot light 99 may be a. red light and the running pilot light I00 may be a green light. If the starting or red light is extinguished before the green light turns on, the operator will know that the cranking limit switch I28 has opened. It may be manually reset or it may be of the type which will reset itself when it has cooled sufllciently.

The engine speed is governed by a governor I5 of any suitable construction, the arrangement being such that the spring II tends to open the throttle while the governor I5, acting against the spring II, tends to close the throttle. .The tension of the governor spring I? will govern the speed at which the engine will operate. Under conditions of high load, the pressure existing in the suction pipe 44 is high. Under these conditions, it is desirous that the engine be permitted to run at a little higher speed to take care of the increased load. It will be observed that the suction line 64 communicates with the Sylphon bellows through a pipe 64'. As the pressure in the suction line rises, the Sylphon bellows expands, moving the lever I52 to the left, increasing the tension of spring I I. Figures 1 and 2 is diagrammatic. As the load decreases, the pressure in the suction pipe 44 drops. Under these conditions, it is unnecessary that the engine run at the set speed, a slower speed being more preferable. This is automatically taken care of by-a contraction of the bellows 65, permitting less tension on the governor spring I1, permitting the governor I5 to move the throttle I6 toward closed position.

Referring now to Figure 7 of the drawings, the engine modulation control just generally described is shown in detail. The governor housing is indicated by a reference numeral I53. The governor is run by the engine in any suitable manner and controls a shaft I54 to which a throttle lever I55 is keyed. The arrangement is such that, as the engine tends to exceed its set speed, the shaft I54 will rotate clockwise, moving the link I56 to the right as viewed in Figure 7, operating the throttle operating arm I51 to move the throttle to closed position, against the action of spring I 1. One end of the spring I I is secured to the lower end of the lever I55. The other end of spring I! is secured to one leg of a bell crank lever I58 as can readily be seen by reference to Figure 7. A housing I59 encloses a Sylphon bellows B5. A spring I60 mounted within the housing urges the bellows to expanded position. A shaft I6I is mounted to move with the movement of the free end of the Sylphon bellows 65. The pipe 64 communicates with the suction side of the compressor. An increase in pressure in pipe 64', as would be occasioned by a heavy load, tends to compact the Sylphon bellows 65 against the action of spring I60, thus moving the rod I6I downwardly. Rod I6I is secured to the other leg of the bell crank lever I58. Downward movement of the rod I60 rotates the bell crank lever around its pivot I62 in a counterclockwise direction, thus increasing the tension on spring I1 and tending to open the throttle against the action of the governor. Should the load become decreased, the suction pressure will drop, permitting the spring I60 to expand the Sylphon bellows, moving the rod IGI upwardly The showing in and rotating the bell crank lever ill in a clockwise direction, decreasing the tension on spring I1 and permitting the throttle to move toward closed position under the action of the governor.

Referring now to Figure I, which shows the high-low control Sylphon bellows I63 communicates with the discharge pipe 20 of the compressor through pipe 62. Sylphon bellows I64 communicates with the suction line of the compressor through pipe 64. Contact point I50 is carried by the free end of bellows I64. A contact point I5I is carried upon a lever I65, pivoted at I 66. The other end of lever I65 is secured to the Sylphon bellows I63 and a drop in pressure in the suction line of the compressor will tend to contract bellows I64, moving contact point I50 upwardly, tending to break the ignition'circuit through conductors I39 and I40. An increase in pressure in the discharge side of the compressor tends to expand Sylphon bellows I63, pivoting the lever I65, moving the contact point I5I downwardly away from contact point I50, tending to break the circuit. The pressure at which the circuit is broken is governed by the compression of spring I61 which is adjusted through adjusting knob I68. An increase in the spring tension I61 will tend to maintain contact points I50 and lil in contact through a greater reduction in pressure on the suction side and a greater increase in pressure on the pressure side.

Referring now to Figures 3, 4, and 5, I have shown the construction of my master control switch or commutator. The upper portion of the assembly comprises a cylinder 81 in which is housed a spring 89 and a piston 08. A piston rod I69 extends into a block I10 of insulating material. The block I10 carries the various commutator bars 12, 15, 18, 8|, and 84. The end of piston rod I10 is provided with an enlarged portion I12, adapted to contact the upper end of the block 215. It will be observed that there is considerable lost motion between the piston rod I69 and the'switch block 10. This arrangement permits the engine to start properly and prevents operation of the switch block upon the first few revolutions of the engine. The arrangement in sures that the engine will be properly running before the switch block is shifted from the position it occupies in Figure 1 to that which it occupies in Figure 2. The lower end of the switch block I10 is guided by dowel pins I13 and tit. In the drawings in Figure 3, the switch is shown in its lowermost position, that is, with commutator bars l2, l5 and 18 in circuit-making position. A housing I15 protects the assembly. The lower end of piston 88 is open to the atmosphere through a vent I16.

It will be observed that I have accomplished the objects of my invention. I have provided an air conditioning assembly powered by an internal combustion engine, automatically controlled by means of a thermostat. I have eliminated the use of clutches with the incident wear, weight and difficulties involved. My assembly is entirely automatic. The engine operates only when required. It is light in weight and compact. It is adapted to cool an automobile omnibus independently of the omnibus motor. The unloading arrangement insures that the engine be started and attain operating speed before the load is placed thereon. My unit is flexible and may be readily installed in such vehicles as motor omnibuses without materially increasing the weight of the bus and without reducing the space allotted to passengers. The engine and compressor assembly may be located at one point and, because of the generator and motor arrangement for operating the evaporative condenser, the condenser may be located at another point, thus enabling the employment of all available space, irrespective.

of its location.

It will be understood that-certain features and subcombinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my-claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In an air conditioning assembly, an internal combustion engine having an ignition circuit, a refrigerant fluid compressor with a driving connection from said engine, said compressor having a. refrigerant fluid discharge pipe and a refrigerant fluid suction pipe, a pipe providing communication between said discharge pipe and said suction pipe, a valve in said intercommunicating pipe, an electromagnet for actuating said valve, a shut-oil valve in said discharge pipe, at second electromagnet for operating said shut-off valve, a starting motor for said internal combustion engine, a master control switch adapted to control a plurality of circuits, a thermostat, a source of potential, a circuit including said thermostat and said master switch for energizing said ignition circuit, a circuit including said master switch and said thermostat for energizing said starting motor, a circuit including said master switch for energizing said first electromagnet to hold said intercoznmunicating valve in open position, said three crouits being completed by said master switch when it occupies a first position, a second control switch, means responsive to a function of the operation of said compressor for operat.

ing said second control switch, a second ignition circuit including said master switch and said second control switch, a circuit including said master switch and said thermostat for energizing said second electromagnet to hold said'shut-ofi valve in open position, said last named circuits being adapted to be completed by said master switch in a second position, and means responsive to a function of the operation of said internal combustion engine for moving said master switch from said first position to said second position, the construction or said master switch being such that said second igmtion circuit is completed before said first ignition circuit is broken.

2. In an air conditioning assembly, an internal combustion engine having an ignition circuit, a refrigerant fluid compressor with a driving connection from said engine, said compressor having a refrigerant fluid discharge pipe and a refrigerant fluid suction pipe, a pipe providing communication between said discharge pipe and said suction pipe, a valve in said intercommunicating pipe, an electromagnet for actuating said valve, a starting motor for said internal combustion engine, a master control switch adapted to control a plurality of circuits, a thermostat, a source of potential, a circuit including said thermostat and said master switch for energizing said ignition circuit, a circuit including said master switch and said thermostat for energizing said starting motor, a circuit including said master switch for pressor having a discharge pipe for compressed refrigerant fluid and a suction pipe for expanded refrigerant fluid, an internal combustion engine drivingly connected to said compressor, an ignition circuit for said internal combustion engine,

said ignition circuit including a switch, meansv I responsive to a function of the operation of said compressor for controlling said switch, a valve in said discharge pipe, an electromagnet holding said valve in open position, said electromagnet having an operating circuit including a thermostat, the construction being such that said valve will be held in open position by said electromagne't, when the circuit is completed through the thermostat, whereby when said thermostat moves to open the circuit through said electromagnet said valve will close, altering the operation of said compressor to operate said switch to open said ignition circuit.

4. In an air conditioning assembly, a refrigerant fluid compressor, a discharge pipe for compressed refrigerant fluid, a suction pipe for supplying expanded refrigerant fluid to said compressor, a check valve in said discharge pipe, a shut-d valve in said discharge pipe, means for driving said compressor, means responsive to the closing of said shut-off valve for rendering said driving means inoperative, a pipe providing com- 'ni'unicationbetween said dischargepipe and said suction pipe, a valve in said intercommunicating pipe whereby, when said compressor is stopped,

it may be unloaded by opening said intercomplying expanded refrigerant fluid to said campressor, a check valve in said discharge pipe, 9. shut-oil valve in said discharge pipe, means for driving said compressor, means responsive to the closing of said shut-oil valve for rendering said driving means inoperative, a pipe providing communication between said discharge pipe and said suction pipe, a valve in said intercommunicating pipe whereby, when said compressor is stopped, it may be unloaded by opening said intercommunicating pipe valve to permit the compressed refrigerant fluid between said check valve and said compressor to expand in the evacuated suction pipe between said shut-off valve and-said compressor, and means responsive to the,nonoperation of said driving means for opening said intercommunicating pipe valve.

6. In an air conditioning assembly, a refrigerant fluid compressor, an internal combustion engine directly connected thereto for driving the same, a master control switch for controlling the starting and operation of said engine through a thermostat, said master control switch being adapted to be moved to different positions during the starting of the internal combustion engine and during operation thereof, and means responsive to a function of the operation of said engine for moving said master control switch.

7. In an air conditioning assembly, a fluid refrigerant compressor, an unloader valve for said compressor, an internal combustion engine directly connected to said compressor for driving the same, an electric starting motor for said internal combustion engine, a master control switch adapted to control said unloader valve and said starting motor, said master control switch comprising a commutator block, a cylinder, a piston, a piston rod for operating saidcommutator block, fluid pressure means responsive to a function of the operation of said engine for operating said piston to move said commutator block, the construction being such that after said engine has been started, said starting motor will be deenergized and said unloader valve will be closed by the movement of said master switch, thus permitting the engine to start under no load conditions.

JAMES P. GOGGINS. 

